基于脱乙酰基魔芋葡甘聚糖固定酶的H2O2生物传感器

对魔芋葡甘聚糖进行了脱乙酰基改性处理,并用红外光谱表征了其脱乙酰基前后的结构变化.探讨了脱乙酰基魔芋葡甘聚糖溶胶-凝胶的制备条件对其成膜性能及酶固定化的影响.将脱乙酰基魔芋葡甘聚糖用于辣根过氧化物酶的固定,制备出了H2O2生物传感器.传感器在优化的工作条件下线性范围为1.0×10-6 ～6.0×10-4 mol/L,检出限为8×10-7 mol/L,稳定性良好.实验表明脱乙酰基魔芋葡甘聚糖是一种适用于生物传感器领域酶固定化的优良材料.     

离子液体和KGM修饰电极上的直接电化学

将血红蛋白固定在用室温离子液体和魔芋葡甘聚糖(KGM)水凝胶修饰的玻碳电极上,其循环伏安扫描显示一对可逆的氧化还原电流峰,克式量电位(-0.38V,vs.SCE)随溶液pH值的增大而负移,呈良好的线性关系,斜率为51 mV/pH,表明在离子液体和KGM共同修饰的电极上包埋在魔芋葡甘聚糖水凝胶中的血红蛋白发生了直接可逆的电子传递反应,并伴随有一质子的迁移过程.此外,还考察了该血红蛋白修饰电极对O2还原反应的电催化性能.     

羧甲基交联魔芋葡甘聚糖微球的制备与表征

采用交联魔芋葡甘聚糖颗粒(CKGG)合成了羧甲基交联魔芋葡甘聚糖微球(CMCKGG)，讨论了羧甲基化过程中的影响因素．用正交设计的方法确定了具有较好交换容量的CMCKGG制备奈件．当碱用量为CKGG量的20％，氯乙酸钠用量为CKGG量的10倍，温度55℃，反应时间8h时，制得的CMCKGG阳离子交换容量为0．7389mmol／g．红外光谱．光学显微镜和扫描电镜的结果表明，该颗粒为蜂窝状多孔微球，粒度均匀．     

葡甘聚糖凝胶及其衍生物研究(Ⅰ)

以魔芋葡甘聚糖为原料合成了葡甘聚糖凝胶(GM)和它的衍生物DEAE—GM弱碱性阴离子交换树脂。GM凝胶具有较好的碱、酸和热稳定性;具有分子筛作用;能把单糖和大分子多糖分开,能除去蛋白质制剂中的盐类。DEAE—GM的全交换容量是2.92—3.23mmol/g树脂,工作交换容量是40.8—42.2mg(牛血红蛋白)/ml树脂;对牛血清白蛋白的吸附量是15.76mg/ml树脂,并可以把羊红血球超氧化物岐化酶粗酶制剂分离成几个组份。此外,吸附固定化环状糊精葡基转移酶活性达3023.5u/g树脂。     

纤维素酶降解-离子色谱法测定魔芋中的亚硝酸盐

建立了以纤维素酶降解魔芋葡甘聚糖释放阴离子,然后采用离子色谱测定亚硝酸盐含量的方法。考察了纤维素酶降解葡甘聚糖的最佳条件,结果表明:在50 ℃、pH 5.5条件下酶解24 h,可以释放出被包埋的亚硝酸盐。NO-2的检出限为0.039 mg/L,回收率为96.7%～97.8%。运用本法对施用稀土微肥后魔芋中亚硝酸盐的含量进行测定,发现施用稀土微肥能够在一定程度上降低魔芋中亚硝酸盐的含量。     

交联羧甲基魔芋葡甘聚糖吸附重金属离子的研究

以异丙醇为分散剂,环氧氯丙烷为交联剂,在碱性介质中由一氯乙酸和魔芋葡甘聚糖(KGM)反应,制备了取代度为0.265和0.550的两种交联羧甲基魔芋葡甘聚糖(CMKGM),并将其用于吸附溶液中Cu2 、Pb2 和Cd2 。结果表明,CMKGM对3种重金属离子的吸附约在20min内达到平衡,与金属离子类型无关,吸附遵从二级动力学方程;pH对吸附量影响较大,适宜范围为5~6;吸附能较好地服从Langmuir等温吸附方程,CMKGM(DS=0.550)吸附Pb2 的最大吸附容量(Qm)为41.7mg/g,Langmuir常数(b)为0.305mg/L,均大于Cu2 和Cd2 相应值;再生后的CMKGM吸附性能好,脱吸附百分率高。     

氧化魔芋葡甘聚糖的结构研究

以魔芋精粉为原料采用乙醇纯化法制得纯化魔芋葡甘聚糖,进一步用悬浮法和湿法制备氧化魔芋葡甘聚糖(O-KGM),采用DSC、XRD、SEM、IR、量子化学计算等方法对O-KGM的结构进行预测和表征。结果分析表明,氧化主要发生在糖残基的C(2)及C(3)位,O-KGM的特性粘度降至272.9 cm3/g,约为改性前的1/7,玻璃化温度及晶体熔融温度分别为61.5 和149.36 ℃,同时结晶度略有增加。     

魔芋葡甘聚糖磷酸酯对高岭土悬浊液的絮凝研究（Ⅰ）

魔芋葡甘聚糖磷酸酯对高岭土悬浊液的絮凝研究（Ⅰ）奉平陈旭东（西南师范大学环境化学研究所重庆，６３０７１５）（华南理工大学高分子系广州，５１０６４１）杨大成，付英姿（西南师范大学化学系重庆，６３０７１５）关键词：魔芋葡甘聚糖磷酸酯（ＫＧＭＰ），高岭土，...     

交联羧甲基魔芋葡甘聚糖空心微球制备及应用

以魔芋葡甘聚糖(KGM)为壁材,通过羧甲基化并经乳状液化学交联制备球体较为完好的羧甲基魔芋葡甘聚糖(CMKGM)空心微球.通过扫描电镜(SEM)和透射电镜(TEM)对CMKGM空心微球的形貌和粒径进行了表征.结果表明,KGM溶胶浓度为0.5%-1%、乳化剪切速率为8000r/min、环氧氯丙烷(ECH)为5ml时,可以得到粒径均匀、形貌规整、溶胀性能良好的CMKGM空心微球.增大溶液的pH和羧甲基试剂的用量均有利于CMKGM空心微球对水中Cu2+的吸附.     

魔芋葡甘聚糖/聚乙烯醇纳米纤维膜及其释药行为研究

为了研制药物缓释效果优良的薄膜材料,利用静电纺丝设备研制不同比重的魔芋葡甘露聚糖/聚乙烯醇纳米纤维膜,并通过扫描电镜、傅里叶变换红外光谱和示差扫描量热法表征纳米纤维膜的结构和性能,结合体外实验和数学模型研究其缓释行为.结果显示当魔芋葡甘露聚糖含量占纳米纤维膜总质量约76%时,纳米纤维膜中微纤丝粗细最均匀且结点较少,纳米纤维膜中魔芋葡甘聚糖和聚乙烯醇之间存在明显的相互作用,含有5-氨基水杨酸的纳米纤维膜在pH=7.4 PBS磷酸盐缓冲液中25 h的累积释放量大约为45%,显示出良好的药物缓释效果,其缓释行为与Higuchi模型具有较高的拟合度.研究表明利用静电纺丝设备研制的魔芋葡甘聚糖/聚乙烯醇纳米纤维膜可以为药物缓释载体的开发提供理论依据.     

Sinopak-s-DEAE高效弱阴离子交换色谱填料的研究

以多孔硅胶为基质,用改进的合成方法制备了Sinopak-s-DEAE高效弱阴离子交换色谱填。考察了反应条件对填料合成的影响,并以标准蛋白为样品进行了色谱行为的研究,结果表明：所制备的填料对蛋白质的分离性能良好,且对蛋白质的非特异性吸附小。     

四种国产固体基质用于室温燐光法的考察及比较——国产微晶纤维素膜、阴离子交换纤维素膜、硅胶G胶片和定量滤纸

本文对国产微晶纤维素膜、阴离子交换纤维素膜、硅胶 G 胶片用于 SS-RTP 的可行性结合氟哌酸和对氨基马尿酸的研究进行了考察,并与国产滤纸进行了比较,详细比较了基质的激发和发射特性、温度效应、重原子对基质背景的影响及 pH 影响等,结果表明,上述新型固体基质较滤纸在不同程度上具备作为 SS-RTP 中衬底的良好性能。这对进一步扩大基质的应用范围是有意义的。     

批量离子交换层析和凝胶过滤层析在类人胶原蛋白I纯化中的应用

研究了利用批量离子交换层析与凝胶过滤层析相结合的方法纯化类人胶原蛋白I的最佳条件。分别考察了不同离子交换树脂、缓冲溶液pH、离子强度、进料蛋白浓度对批量离子交换的影响,以及不同凝胶过滤介质对凝胶过滤层析的影响。结果表明,采用阴离子交换树脂DEAE52吸附杂蛋白,缓冲液pH为7.0,NaCl浓度为0.2mol/L,进料蛋白浓度为40mg/mL,并采用凝胶过滤介质SephadexG-100进一步纯化后,类人胶原蛋白I的纯度可达到98.2%,总纯化倍数为3.1,总回收率为80.6%。SDS-PAGE分子量分析和N末端氨基酸序列分析均表明纯化后的类人胶原蛋白I与基因设计一致。     

Separation and determination of emetine dithiocarbamate metal complexes by capillary electrophoresis with chemiluminescence detection of the tris(2,2'-bipyridine)-ruthenium(II) complex

A new cellulose-based anion-exchanger was prepared by grafting polyallylamine onto cellulose. The material was obtained by partial oxidation of a size-exclusion grade cellulose gel by aq. NaIO4, forming dialdehyde cellulose, followed by Schiff base formation with a polyallylamine (PAA, molecular mass 5000) and subsequent reduction for stabilization. Three grades of PAA-cellulose gels, with amino group contents of 0.78, 1.01 and 1.28 mmol/g cellulose, were examined for their ionic interaction with mono- and divalent carboxylic acids at pH 2.5-5.5. While the retention factor for monovalent acids was nearly proportional to the amino group content of the gel, that for divalent acids was remarkably greater for the PAA-cellulose gel than for the conventional diethylaminoethyl (DEAE) cellulose gel bearing more amino groups (1.97 mmol/g cellulose). Such high capacity can be explained by the high local density of amino groups on grafted PAA, in contrast to the random and sparse charge distribution in conventional exchangers.     

Molecular Dynamics Simulations of the Interactions between Konjac Glucomannan and Carrageenan

The interactions between konjac glucomannan and carrageenan were studied with the method of molecular dynamics simulation. Part representative structure segments of KGM and two unit structures of κ-carrageenan （Fig. 2） were used as mode, and the force-field was AMBER2. The stability and sites of konjac glucomannan/carrageenan interactions in water were researched at 373 K with the following results： the potential energy （EPOT） of the mixed gel was dropped, while those of single-konjac glucomannan gel and single carrageenan were increased. The surface area （SA） of KGM in the mixed system was decreased to 1002.2A^°^2, and that of carrageenan to 800.9 A^°^2. The variations of two parameters showed that the stability of compound gel konjac glucomannan/carrageenan was improved, which is consistent with the previous studies. The sites of interactions in the mixed gel were the -OH groups on C（2）, C（4） and C（6）, the acetyl group in KGM mannose, and the -OH group on C（6） in carrageenan. The hydrogen bond was formed directly or indirectly by the bridge of waters.     

Preparation, Properties and Mechanism of Inhomogeneous Calcium Alginate Ion Cross-linking Gel Microspheres

Inhomogeneous calcium alginate ion cross-linking gel microspheres,a novel ion absorbent,were prepared by dropping a sodium alginate solution to a calcium chloride solutioin via an electronic droplet generator.Calcium alginate microspheres have uniform particle sizes.a smooth surface and a microporous structure.The electrode probe reveals the inhomogeneous distribution of calcium ions with the highest concentration on the surface,and the lowest concentration in the cores of the spheres.As a novel ion adsorbent,calcium alginate gel microspheres have a lower limiting adsorption mass concentration,a higher enrichment capacity and a higher adsorption capacity for Pb^2 than usual ion exchange resins.The highest percentage of the adsorption is 99.79%.The limiting adsorption mass concentration is 0.0426mg/L.The adsorption capacity for Pb^2 is 644mg/g,Calcium alginate gel microspheres have a much faster ion exchange velocity than D418 chelating resin and D113 polyacrylate resin.The moving boundary model was employed to interpret the ion exchange kinetics process,which indicates that the ion exchange process is controlled by intraparticle diffusion of adsorbable ions.So the formation of inhomogeneous gel microspheres reduces the diffusion distance of adsorbable ions within the spheres and enhances the ion exchange velocity.Alginate has a higher selectivity for pb^2 than for Ca^2 and the selectivity coefficient KCa^Pb is 316. As an ion cross-linking gel,calcium alginate inhomogeneous microspheres can effectively adsorb heavy metal Pb^2 at a higher selectivity and a higher adsorption velocity.It is a novel and good ion adsorbent.     

利用磷肥副产物硅渣制备亚微米4A分子筛

以磷肥副产物硅渣制备的硅胶湿样和氢氧化铝为原料,溶胶-水热法合成了亚微米4A分子筛,采用XRD、SEM和FT-IR等分析手段进行了表征.结果表明采用硅胶湿样制备的产品形状规则、大小均匀;干基分子筛相对于CaCO3的钙离子交换容量为340 mg/g,白度为95%,与常规水热合成法制备的产品相比,其粒度较小、分布范围较窄,钙离子交换容量有很大提高.     

Synthesis and Properties of IPN Hydrogels Based on Konjac Glucomannan and Poly（acrylic acid）

As a random copolymer of β-(1,4) linked D-mannose and D-glucose, konjac gluco- mannan (KGM) is a naturally occurring water-soluble polysaccharide, and has been paid attention in the field of drug controlled release carriers potentially used in colon1,2. …     

Synthesis and characterizations of new negatively charged organic–inorganic hybrid materials: effect of molecular weight of sol–gel precursor

A series of negatively charged hybrid (organic–inorganic) materials were prepared through sol–gel process. The alkoxysilane-containing sol–gel precursors PEO-[Si(OEt)₃]₂SO₃H were obtained by endcapping polyethylene oxide (PEO) of different molecular weights with 2,4-diisocyanate toluene (TDI), followed by a coupling reaction with phenylaminomethyl triethoxysilane (ND-42) and sulfonation afterwards. The negatively charged precursors were then hydrolyzed and condensed to generate hybrid sol–gel materials, which were characterized by IR, TGA, XRD as well as the conventional ion exchange measurements. The results showed that in the hybrid sol–gel precursors PEO-[Si(OEt)₃]₂SO₃H organic PEO component was incorporated with alkoxysilane-containing ND-42 covalently. As the molecular weight of the precursors increased, thermal stability and cation-exchange capacity of the hybrid material decreased. All the hybrid materials were amorphous and those prepared from higher molecular weight precursors were flexible.